There are many embedded appliccations for website that are very tiny 4 mb for a server, such as cherokee? Just filter http: address to be replaced by email address?

http://www.linuxdevices.com/articles/AT5550934609.html

With lighttpd, the server can have double the load, by load balancing off to another server.

Apache can have very good speed, almost double, using lighttpd. Understand SourceForge.net uses lighttpd.